Wise is he who dares to know!

Oxford University Interview Questions

Waiting for university interviews? Perhaps Oxford? Wondering what some of the questions might be like?

Look at these sample interview questions from Oxford Interviewers to get some idea...

If you’re waiting for a call for an interview right now, then you might be wondering what kind of questions your interviewer might ask.

Generally, it is common knowledge that universities like Oxford and Cambridge are interested in seeing the way you think. They are not necessarily concerned with whether you know the answer or not – often they know that you don’t know – they deliberately throw you a hard question, just to see how you can apply your knowledge to find your way out of the conundrum.

Here are a few sample interview questions from Oxford University (by subject).

Biochemistry

Interviewer: Mark Wormald, Corpus Christi College

Here is a list of three compounds, A, B and C. Which one is most soluble?(A, B and C will be specific simple compounds which the candidate should recognise.)

We expect most candidates to say that they don’t know and that’s completely fine – what we are looking for is how the candidate works through the problem. (If someone does already know the answer, we’d move on to another line of questioning.)

I’d help the candidate to try to work out the answer by building a hypothesis that could then be tested. This usually involves a discussion about the factors that might affect solubility, looking at the bonds that hold the solid together. This will call on the students’ knowledge of the specific compounds in the list, the nature of the bonding, and how to predict which types of bonding are stronger than others. This requires the students to provide more detailed chemical analysis, which reveals the depth of their understanding.

Once the student has reached a hypothesis that predicts the order of solubility (eg A > C > B) I may tell them that the correct order is actually something else, and then discuss the possible reasons for the discrepancy. It’s not about the accuracy of the student’s thinking, since we don’t actually expect them to get the right answer. It’s more about how they react to getting the answer wrong, and how motivated they are to identify all the possible sources of error so that they can then test and eliminate each one in turn. We want them to question their assumptions and find ways to test those assumptions.

This might lead in to a conversation about ways you might test the strength of the chemical bonds in different solids. For example, you could heat the solid but then heating might have other unwanted effects. I want the students to demonstrate their understanding of those other effects, and to call on a wide range of knowledge of Chemistry when answering each question.

Biological Sciences

Interviewer: Owen Lewis, Brasenose College

Why do some habitats support higher biodiversity than others?

This question encourages students to think about what high-diversity habitats such as rainforests and coral reefs have in common. In many cases, patterns or correlations can help us to identify the underlying mechanisms. For example, a student might point out that both rainforests and coral reefs are found in hot countries and near the equator. The best answers will attempt to unravel exactly what it is about being hot or near the equator that might allow numerous types of plant and animal to arise, persist and coexist. Do new species evolve more frequently there, or go extinct less frequently? Once students have come up with a plausible theory, I’d follow up by asking them how they would go about testing their idea. What sort of data would they need?

Interviewer: Martin Speight, St Anne’s College

Why do many animals have stripes?

The main aim of the question is to get applicants to think about biological topics and put them in the context of successful adaptations to life on earth. So I might expect students to start by thinking of some stripey animals, then move on to thinking about categories of striped animals – for

example those that are dangerous (such as wasps, tigers, and snakes), those that have stripes for camouflage (such as zebras but also tigers), and those whose stripes are harmless mimics of dangerous ones. They might think of specific examples for detailed comparison: tigers and zebras for example both have stripes for camouflage and blending in with background, one to hide from prey and the other to hide from predators.

Other things that would be worth considering include whether stripes may only occur in the young of a species; whether the colour of the stripes matters rather than just the contrasting stripe pattern, and why do stripe size, shape, width and pattern vary in different species. There are no right or wrong specific answers to the questions – I’m just interested in candidates’ speculations about the advantages of having stripes.

Here’s a cactus. Tell me about it.

We wouldn’t actually phrase the question this way – we give the student a cactus in a pot and a close-up photo of the cactus’s surface structure and ask them to describe the object in as much detail as possible using the plant and the photo. We are looking for observation, attention to detail, both at the large and micro scale. We ask them to account for what they see – this means they don’t have to use memory or knowledge about cacti (even if they have it) but to deduce the uses and functions of the shapes, sizes, structures that they have just described. So for example, why be fat and bulbous, why have large sharp spines, surrounded by lots of very small hair-like spines? Why does it have small cacti budding off the main body? There will frequently be more than one logical answer to these questions, and we are likely to follow one answer with another question – for example:

‘The big spines are to stop the cactus being eaten, yes, but by what sort of animals?’ We would also bring in more general questions at the end of the cactus discussion, such as what are the problems faced by plants and animals living in very dry habitats such as deserts.

If you could save either the rainforests or the coral reefs, which would you choose?

I’d expect students to be able to use their general knowledge plus their common sense to come up with an answer – no detailed knowledge is required. Students might then be asked about the importance of natural features, such as biodiversity and rare species, and human interests, such as the fuel and food, ecotourism and medicines we get from rainforests or reefs. Finally there are impacts to consider from climate change, soil erosion, pollution, logging, biofuel replacement, overfishing, etc. The final answer doesn’t matter – both reefs and rainforests must be managed sustainably to balance conservation and human needs.

Is it easier for organisms to live in the sea or on land?

Firstly candidates should define ‘easier’ – does it mean less complexity, less energy expenditure, less highly evolved, less likely to be eaten etc? Then candidates could think of problems caused by living in the sea, such as high salinity, high pressure, lack of light etc. Problems living on land include extra support for the body, avoiding desiccation, the need for more complex locomotory systems (legs, wings etc) and hence better sensory and nervous systems etc. Then ask in which of the two ecosystems have animals and plants been more successful? So now they have to define ‘successful’…

Interviewer: Owen Lewis, Brasenose College

Why do lions have manes?

Some of the best interview questions do not have a ‘right’ or a ‘wrong’ answer, and can potentially lead off in all sorts of different directions. Applicants might have picked up ideas about the function of a lion’s mane from independent reading or from watching natural history documentaries. That’s fine – but I’d follow up their response by asking how they would test their theory. When I’ve used this question in interviews I’ve had all sorts of innovative suggestions, including experiments where lions have their manes shaved to investigate whether this influences their chances with the opposite sex or helps them win fights over territory.

Ladybirds are red. So are strawberries. Why?

Many Biological Sciences tutors use plant or animal specimens – often alive – as a starting point for questions and discussion, so applicants shouldn’t be surprised if they are asked to inspect and discuss an insect or a fruit. Red can signal either ‘don’t eat me’ or ‘eat me’ to consumers. I’m interested in seeing how applicants attempt to resolve this apparent paradox.

Would it matter if tigers became extinct?

This question is not about hoping students will display their expert knowledge of tigers. Most applicants would instinctively answer ‘Yes…’, but it is the ‘because….’ that interests me, and can help to distinguish critical thinkers. I might follow up this question by asking if it would matter if less glamorous creatures – like fungi – went extinct.

Biomedical Sciences

Interviewer: Robert Wilkins, St Edmund Hall

Why is sugar in your urine a good indicator that you might have diabetes?

This question builds on general knowledge and material studied at school in biology and chemistry to assess how students approach a clinically-relevant problem. It’s commonly known that diabetes is associated with sugar (glucose) in the urine; this question asks students to think about why this occurs. Students have usually have learnt that the kidneys filter blood to remove waste products, such as urea, that must be eliminated from the body but many other useful substances which must not be lost – including glucose – are also filtered. Given that glucose is not normally found in the urine, students are asked to speculate as to how it can all be recovered as the urine passes through the kidney’s tubules.

The process involves reabsorption by a carrier protein that binds the glucose molecules and moves them out of the renal tubule and back into the blood. Students should appreciate that, in binding glucose, the carrier will share properties with enzymes, about which they will have learned at school: the capacity to reabsorb glucose is finite because once all of the carriers are working maximally, no further glucose reabsorption can occur. A successful applicant will make the connection that an elevated level of glucose in the blood in diabetes leads to increased filtration of glucose by the kidneys and saturation of the carriers that perform the reabsorption, resulting in ‘overspill’ of glucose in the urine.

Interviewer: Jan Schnupp, St Peter’s College

Why do a cat’s eyes appear to ‘glow’ in the dark?

This question builds on commonly held knowledge and on material covered in Biology at school about visual processes. The question assesses criteria such as scientific curiosity (has the applicant ever wondered this themselves? Have they formulated any theories?) and scientific reasoning, based on information provided by the interviewer as the interview progresses. After establishing that the applicant understands that light is detected by photoreceptors in the eye (and exploring and explaining this concept if it is a new one), the discussion would consider how the glow might be advantageous to the cat, seeing whether the applicant can appreciate that it may help the animal to see in the dark. Possible explanations for the glow would be discussed with an expectation that applicants might recognise that the light could be generated within the eye or alternatively that light entering the eye is in some way reflected back out. Having established the second possibility as more being more plausible, the interviewer would probe to see whether the candidate recognises the significance of giving photoreceptors two chances to capture light as rays pass into and then out of the eye and why at night this might enhance vision.

Economics

Interviewer: Terry O’Shaughnessy, St Anne’s College

The Holiday Puzzle:

“Alex and Brian are cousins. They are planning a four-day holiday in Venice and they each have 400 euros to spend. (They have already paid for their return flights and for their hotel room.) On the flight to Venice Alex and Brian discuss how they should each allocate their spending over the four days.

Alex believes that the satisfaction he gains from spending a certain amount x euros on a given day is proportional to √x. Explain why this might be a reasonable way to represent his preferences. If he has these preferences how would you expect him to allocate his spending over the four days?

Brian has the same preferences as Alex, but he knows that he tends to be impatient. This means that, on any given day, he tends to give extra weight to the current day’s spending when he makes his spending decisions for that day. Thus on a given day he behaves as if the satisfaction he would gain from spending x euros would be √(2x) whereas the thinks that on subsequent days the satisfaction he will gain from spending x euros will be only √x.

If Brian has these preferences how would you expect him to allocate his spending over the four days?

Is there a better way for Brian to allocate his spending and, if so, how might he achieve this better outcome?

Does your analysis of this problem have any implications for any current economic policy issues?”

After asking one or two general questions such as ‘what topic in Economics have you enjoyed most, or found most surprising’ we move on to working through a puzzle. We give the candidate a copy 10 minutes before the interview starts. We might spend 10-15 minutes going through the implications of the puzzle during the interview, though this depends on how far candidates get, and how quickly they get there!

Each puzzle is designed to see how willing candidates are to abstract from the complexities of a ‘real world’ case involving some economic principles and to put such principles ‘to work’. There is usually some simple mathematical ideas involved (in this case, the idea that the utility function provided implies that it is best to allocate spending uniformly over the four days). However, we do not expect any calculations to be performed, though drawing a diagram is often useful (as it is in this example).

Economics and Management

Interviewer: Brian Bell, Lady Margaret Hall

Do bankers deserve the pay they receive? And should government do something to limit how much they get?

This is a very topical question in light of the recent financial crisis. A simple answer might be that since banks are generally private firms and workers are free to work where they wish, then the pay they receive is just the outcome of a competitive labour market. In this story, bankers earn a lot because they are very skilled and have rare talents. It is hard to see a reason for government intervention in this case – though on equity grounds one may want to have a progressive income tax system that redistributes some of this income. A good candidate would wonder why it is that seemingly equivalently talented people can get paid so much more in banking than in other occupations. Do we really believe that bankers are so much better than other workers in terms of skill? An alternative story is that the banking industry is not competitive and generates profits above what a competitive market would produce. This would then allow workers in that industry to share some of those profits and so earn much more. In this case, there is a role for government intervention – making the market more competitive. The key point about this question is trying to get candidates to think about the economics of pay rather than just whether they think it is fair or not.

Mathematics

Interviewer: Rebecca Cotton-Barratt, Christ Church

Imagine a ladder leaning against a vertical wall with its feet on the ground. The middle rung of the ladder has been painted a different colour on the side, so that we can see it when we look at the ladder from the side on. What shape does that middle rung trace out as the ladder falls to the floor?

This question tests whether you can do what mathematicians do, which is to abstract away all the unimportant information and use mathematics to represent what’s going on. I’d initially ask the candidate what shape they think will be formed, and then ask them how they can test this hypothesis. They might initially try sketching the ladder at different stages – this is fine, but ultimately what we want is something that we can generalise and that is accurate (you can’t be sure that your drawing is that accurate, particularly when you’re making a sketch on a whiteboard and don’t have a ruler). So eventually they will fall back on maths, and try to model the situation using equations. If they get stuck we would ask them what shape the ladder makes with the wall and floor, and they’ll eventually spot that at each stage the ladder is forming a right-angled triangle. Some might then immediately leap to Pythagoras’ Theorem and use that to find the answer (which is that it forms a quarter circle centred on the point where the floor meets the wall).

This is a fun question because the answer is typically the opposite of what they expect because they think about the shape the ladder makes when it falls (which is a series of tangents to a curve centred away from the wall and the floor). A nice extension is what happens when we look at a point 1/3 or 2/3 up the ladder.

Interviewer: Richard Earl, Worcester College

How many ways are there to cover a 2 x n rectangular grid with 2 x 1 tiles?

The question would typically be posed with the caveat – “I don’t expect you to have the answer straight away; try working out the answer when n = 1,2,3,4 say”. So here is something to investigate. Maths interviews are usually conducted over a piece of paper, sometimes at a white board and so diagrams will get drawn and the student will find the answers are 1, 2, 3, 5 for the first four cases. Some systematic care may be needed to explain why the fourth answer is 5 and why no sixth solution has been missed.

A relatively comfortable few minutes has been spent on this, but it’s also important that the student and I aren’t talking at cross-purposes. At this point I usually tell the student the next two answers at 8 and 13 – any thoughts on the emerging pattern? The answer is the Fibonacci sequence – where a term of the sequence is the sum of the previous two eg 8 = 5 + 3, though it’s not important if the student hasn’t met this before or has forgotten the name. The next stage of the interview is about understanding why that pattern should be appearing here.

When done with this bit of the interview hopefully the student has taken on board a few new ideas. So the question moves on to: 3 x n rectangular grids and 3 x 1 tiles, to 3 x n rectangular grids and 2 x 1 tiles. Hints will continue to be needed, but also there will be plenty of chance to see just how much the student has taken on board from earlier and how well s/he can adapt what’s been learned.

One of the reasons I found this a good question in the past was that its knowledge content is low, no more than GCSE. But its internal complexity is sufficiently difficult to test the brightest students, especially in the final part, whilst also allowing students repeated chances to show what they were learning and share their thinking.

To see more Sample Interview Questions from Oxford University for other Subject Departments click here……